Method and an apparatus of leveling a metal strip

ABSTRACT

An apparatus for leveling a metal strip wherein the strip is made to travel along an elongated guide mounted on a bed. The guide has an outwardly tapered elongated central section with a plurality of guide capillaries and a flat portion at the top of the guide with recesses in the flat portion around each of the capillaries. The moving strip is supported on a fluid fed through the capillaries and is not in contact with the guide flat portion.

United States Patent 1191 Kawaguchi-et al.

1. 11 3,812,697 1451 May 28,1l974 METHOD AND AN APPARATUS OF LEVELING AMETAL STRIP Inventors: Kiyoshi Kawaguchi, Kudamatsu;

Yasunori Miyamatsu, Yokohama; Arao Kamoi, Kudamatsu; Kinya Fukuda,Yokohama, all of Japan Assignee: Toyo Kohan Co., Ltd.', Tokyo, JapanFiled: Feb.'5, 1973 Appl. No.: 329,310

- U.S. CL... 72/60, 72/160 Int. Cl...; B2ld l1/02 Field of Search...'..;72/54, 56, 60, 57,160

References Cited v UNITED STATES PATENTS Ferchland 72/60 3,559,4382/1971 Rouyeretai. .,.;..72/160 3,587,598. 6 1971 Miyamatsuetal...'..'134/122 Primary Examiner- Richard J. Herbst Attorney, Agent, orFirm-George B. Oujevolk [5 7] ABSTRACT Y An apparatus for leveling ametal strip wherein the strip is made to travel along an elongated guidemounted on a bed. The guide has an outwardly tapered elongated centralsection with aplurality of guide capillaries and a flat portion at thetop of the guide with recesses in the Hat portion around each of thecapillaries. The moving strip is supported on a fluid fed through thecapillaries'and is not in contact with the guideflat portion. 1

11 Claims, '21 Drawing Figures Pmmanmzemn $812,697

saw 03 OF 10 mmmwz m4 3812.697

.sum as or 10 FIG." I 15 16 PATENTEDm 28 1914 sum 07 or 10 METHOD AND ANAPPARATUS or LEVELING A METAL STRIP BACKGROUND OF THE INVENTION BRIEFDISCUSSION OF THE PRIOR ART Manufacturing of a metal strip involvesseveral processes such as rolling, annealing and tempering. As the metalstrip is processed, defects concerning the shape of the metal strip,such as guttering, curling, edge wave, full center and quarter buckleappear. These defects are not only obstacles in the following processes,but

also a large factor to lower the quality standard of the products forwhich the metal strip is used. Therefore, it is necessary for the metalstrip to be leveled by using a leveler. Generally, in processing theIeveler, the metal strip is bent plastically several times under tensionby work rolls. During leveling,the 'metal strip is elongated plasticallyaround 0.3 to 1.5 percent and the plastic elongation corrects the shapedefects of the metal strip. The mechanical tension leveler is a knownapparatus for leveling.

It is known generally that when leveling a metal strip by a mechanicaltension-leveler the use of work rolls of as a smalldiameter as possiblehelps to reduce the ten-' sion required to-correct shape defects of themetal of the work roll in theconventional mechanical tension leveler,the mechanism of supporting the work rolls is complicated and the numberof the bearings of back up rollswill increaseto support the work rolls.Other difficulties appear such as stains on the surface of the metalstrip due to leakage of oil out of the bearings and scratches on thesurface due to undesirable vibration by deteriorating accuracy ofmachine elements assembled. Also, there isthe difficulty of reducing thework roll diameter. Even though the mechanism of supporting the smallwork rolls isprovided, the number of rotations of the small work rollbecomes considerably larger than that of the regular work roll for thesame traveling speed of the metal strip, which causes sticking of thebearings and shortens the life of the work rolls. Therefore, it is verydifficult technically to use extremely small work rolls in theconventional mechanical tension leveler. Large tension is required tocorrect shape defects of the metal strip, which means large scalebridles have to be installed before and after the leveler. Further, itis very difficult to practically correct shape defects of cold rolledsteel strip of around 0.1 mm thick.

In-all conventional mechanical tension levelers, work rolls have beenused to bend the metal strip and correct its shape defects. Tension isadded tomake the metal strip fit the surface of the work roll andimprove the effect of leveling. Almost all defects in the conventionalmechanical tension leveler described above are caused by the use ofthe-work rolls. If the metal strip is supported out of contact by fluidfilm and bent without using the work rolls-defects in theconventionalmechanical tension leveler can be substantially avoided. One of theprior art-methods of supporting a strip by a stationary guide andhandling it without causing surface defects is foil hearing. In thiscase, materials such as plastic film metal foil and paper of around 0.3mm to 0.5 mm thick are used. The stiffness of foil is negligibly smallcompared to that of the metal strip to be lev-.

eled and the load capability of the foil bearing is extremely small.Further, the object of foil bearing is not to level the'metal strip. I

Other prior art arrangements are described in US. Pat. No. 3,587,598Sink roll for supporting an elon gate material without direct contact"and British Pat.

No. 1,016,703 Improvements relating to fluid pressure support bearings.But .these patents relate to a technique of supporting the metal stripout of contact and guiding it in a continuous treatment line. Thereforethe object of these arrangements above is different from the presentinvention.

OBJECT OF THE INVENTION Accordingly, it is an object of the presentinvention to provide a method and apparatus for leveling. a metal stripin which work rolls are not used and therefore complicated mechanism isnot necessary to support the work rolls like in the l leveler.

It is another object of the present invention to provide a method andapparatus for leveling a metal strip provide a method and apparatus forleveling the metal I strip in which no scratch is caused to appear onthe surface of the metal strip.-

It is yet a further object of the present invention to', provide anapparatus for leveling the metal strip which i does not have any bearingin the mechanism.

Again, it is an object of the present invention to provide an apparatusfor leveling the metal strip which does not have a limited life of thework rolls in the conventional mechanical tension leveler.

Also, it is an object of the present invention to provide a method andapparatus for leveling the metal strip which does not have any upperlimitations on traveling speed of a metal strip like cal tensionleveler.

SUMMARY OF THE INVENTION Briefly speaking, the principle of leveling ofa metal strip by the present invention is that a traveling metal striphaving shape defects is supported out of contact in'the conventionalmechaniwith the surface of a supporting guide, which does not I have anyrotary part, by a pressure film of liquid and is bent under tension bythe supporting guides, and shape defects of the metal strip arecorrected.

The invention as well as other objects and advantages thereof, will bemore apparent from the following detailed description when takentogether withthe accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of asupporting guide according to the present inventive concept;

conventional mechanical tension FIG. 2 is a cross-sectional view-through.FIG. I along line .I I;

FIG. 3 is a cross-sectional view along line II II of FIG. 1;

FIG. 4 is a perspective view of another type of sup- I porting guideaccording to the inventive concept;

FIG. 5 is a cross-sectional view taken along lines III I in in FIG. 4;

a FIG. 6 is also a perspective view of still another type of supportingguide accordingto the inventive concept;

FIG. 7 is a cross-sectional view along lines IV IV of FIG/6;

FIG. 8 presents yet another perspective view of yet FIG. 13 is also across-sectional view' of a different configuration for some of thecomponents for FIGS. 1, 4and'6; l

FIG. 14 is a perspective view of a'component used with the-embodiment ofFIG. 8;

FIG. 15'is a cross-sectional view taken alon'g lines VII VII of FIG. 14;

FIG; 16 shows a perspective view of the assembly of thecom'ponents inFIGS. 1 and 10;

FIG. 17 is a cross-sectional view taken along VIII VIII of FIG. 16;

FIG. 18 is an'explanation view of one version of a working section of acomplete unit;

lines FIG. 19 is another version of an explanation of a working'sectionof a complete unit; I

FIG. 20 is a schematic version of a complete unit; and,

' FIG. 21 is a schematic explanation of another version ofacompleteunit.

' DETAILED DESCRIPTION FIG. 1 shows a perspective view of a supportingguide 1 with capillary 8. FIG. 2 is a cross-sectional view taken alongthe line I I through capillary 8 in FIG. 1 with a metal strip 28. FIG. 3is across-sectional view taken along the'line ll ll through a hole40 inFIG. 1. A top surface of the supporting guide 1 consists of a flatportion 36 andtwo curved portions 37. A row of capillaries 8 areprovided through the supporting guide 1 to supply pressurized liquid.The capillary 8 has. an opening 4 around which a recess 3 is provided ontheflat portion 36. The capillary 8 has another opening at the bottom'ofthe supporting guide l.,PluraI holes 40 are drilled to measure pressureof a liquid film between the top service and the metal strip 28 to .beleveled. The hole 40 has an opening'6 on the flat surface 36 and anotheropening 9 on the side ofIthe supporting guide 1 to connect to a pressuregage. Plural stepped holes 5 are drilled to fix the supporting guide Ito a bed 2 (see FIG. 10). I I I I I The principle of leveling a metalstrip by the present invention is that the traveling metal strip is bentunder tension by the top-surface of the supporting guide 1 comprisingthellat portion 36 and the two curved portions 37. Pressurized liquidllowsinto the clearance formed between the traveling metal'strip 28 andthe curved portions 37 pressurized liquid film formed be tween thetraveling metal strip 28 andthewp-surface I of the supporting guide .1prevents the metal strip 28 from contacting directly with the'supportingguide 1 and shape defects of the traveling metal strip 28 are corrected.I

In FIG. 4 which is another type of a supporting guide 1, a fin 10 (seeFIG. 5), made of flexible material is at- I tached on each curvedportion 37. The shape of the fin l0 deforms naturally so thatpressurized liquid film is formed in the clearance between the metalstrip 28 and I the top surface of thesupporting guide 1.

In FIG. 6 and FIG. 7 the whole top 11 of the supporting guide 1 is madeof material, such as rubber-and plastic, having lower elasticity than ofthe metal. As shown in FIG. 7, the shape of the top surface does notneed to be curved. Except for the top of the supporting, guide 1, therest of the 38 between the two rows of recesses 4 forms two flatportions 36a. In the embodiments given in FIG. I to 9, the capillaries 8can be replaced withholes having an orifice.

FIG. 10 and 11 are views of a bed 2 on which the supporting guides] inFIG. 1, land 6 are put. The bed 2 contains a chamber 15 inside. Anentrance hole l6is provided to introduce pressurized .liquid frompressure to the chamber 15 and plural holes 14 are drilled to supplypressurized liquid to the capillaries 8 in the supporting guide 1.O-rings 13 are used between the holes 14 and the capillaries 8 toprevent leakage of pressur ized liquid at the joint. Plural holes 12 arethreaded to fix the supporting guide 1 to the bed 2. I

FIG. 12 is a cross-sectional view of abed 2 having an-.

other arrangement for the chambers 15 for the supporting guide 1 inFIGS. 1, 4 and 6. Large-chambers l5 and small chambers 42 are dividedlongitudinally by plural partitions l7 and each chamber 15 or 42 hasindependently an entrance hole 16 or 43 forpressurized liquid I and atleastone hole-1410 supply'pressurized liquid to the capillaries 8. Inthis type of bed 2, the supplyof pressurized liquid to the outer chamber15 can be stopped to save unnecessary flow rate of liquid when a narrowmetal strip is leveled and also the pressure and flow rate of thepressurized liquid to the respective chamber 15 can be changed tocorrect shape defects of the metal strip effectively.

4 FIG. 13 shows another configuration of the chamber 15 for thesupporting guide 1 in FIGS. 1, 4 and 6. In this example, the chamber 15forms a cylinder. At both ends of cylindrical chamber 15, apair ofpistons 19 are provided having a piston rod 18 and O-ring 20. The pis-'tons 19 are movable and can change the length of the chamber 15continuously corresponding to the width of a metal strip to be leveledand so power of the pressure source can be saved.

In FIG. 14 and FIG. 15', the bed 2 contains a of chambers 15b whicbhavetwo rows of entranceholes 16 of pressurized-liquid and holes 14 to thecapillaries 8 of the supporting guide I in FIG. 8. For the assemblycomprising the supporting guide I in FIG. 8 and the bed2 in FIG. 14, twosystems of pressure sources are necessary to supply pressurized liquidinto the chambers' b separately.

FIG. 16 and FIG. 17 shows how an assembly in which the supporting guide1 in FIG. 1 and the bed 2 in FIG. 10 are put together by screws 7. Thejoint between the hole 14 and the capillary 8 is sealed by O-ring 13.The other types of supporting guides 1 and the bed 2, similar to FIGS.16 and 17 can be assembled in the same way.

FIG. 18 is an example of the leveling unit of the metal stripcomprisingthe supporting guides l and the bed 2.

The metal strip 28 is guided to pass between the top surfaces of thesupporting guide 1 which is adjusted above and below by the screw 22 andof the other supporting guide 1 fixed to a lower frame 21. Two deflectorrolls 24 adjustable above and below by screws 22 are disposed before andafter the supporting guides 1. The supporting guides l and the deflectorrolls 24 may be adjusted by using the other known mechanism than screws22. A discharging conduit pipe 27 is connected to the lower frame 21 andsupply conduit pipes 23 are to the supporting guides .1.

'The leveling unit operates as follows:

The supporting guides l are positioned to bend the metal strip28'traveling under tension and at the same time, pressurized liquid issupplied to the supporting guide 1 from the pressure source which is setto supply the liquid under proper pressure and of proper flow rate, andflows out through the clearance 41 between the traveling metal strip 28and the top surface of the supporting guide 1. The wrap angle of themetal strip 28 along the top surface of the supporting guide 1 can bechanged by adjusting the position of the deflector rolls 24..Non-contactbetween the traveling metal strip 28 and the curved portion 37 of thesupporting guide 1 along which pressurized liquid flows outwardly can beattained by adjusting the wrap angle. The traveling metal strip 28 undertension is subjected to bending by the supporting guide 1 out of directcontact and is elongated plastically, and the shape defects of the metalstrip are corrected. b

FIG. 19 is another example of the leveling unit comprising thesupporting guide 1 and the bed 2. The bed 2 is mounted on a rotary part25 which has a cylindrical convex surface to slide on a seat 26. Theseat 26 has a cylindrical concave surface. One of the seats 26 is fixedto the lower frame 21 and two other seats 26 are provided onto the upperframe 30 and adjusted above and below by screws 22. The supply conduitpipe 23 of pressurized liquid is connected to each'bed 2. The otherknown device besides the rotary part 25, the seat 26 and the screw 22can be 'used to change the wrap angle andthe position of the supportingguide 1.

FIG. 20 is an example of a leveler comprising the leveling unit shown inFIG. 18 or 19. The metal strip 28 vention is operated in the similar wayof the conventional mechanical tension leveler. Because no work roll isused in the leveler of the present invention, radius of curvature ofbent metal strip by the supporting guide 1 can be extremely small.Therefore tension required to elongate the metal strip plastically forcorrecting shape defects can be reduced. In FIG. 20 the capacity of thefront bridle 32 and the back bridle 33 can be small. When only smalltension is required, even the bridles used previously in the processingsystem can be utilized and there is not need to use a new bridle for theleveling unit of the present invention. The entire system is shown inFIG. 21. As pressurized liquid, any kind of liquid can be used likewater, lubrication fluids and so on which are used presently in theproduction line. The leveling unit of the present invention has norotary parts like work rolls in the conventional mechanical tensionleveler and therefore the traveling speed of the metal strip is notlimited.

Table 1 shows the sesult of leveling a metal strip by using the presentinvention. Theleveler of the present invention makes it easy to correctthe shape defects of extremly thin and high yield stress metal stripwhich was very difficult to correct by the conventional mechanicaltension leveler.

TABLE 1 Width of flat portion (36) 2.5mm Radius of curved portion (37)2.5mm

Number of supporting guides (1) 3 Front tension between (32) and It willbe understood that various changes and modiflcations can be made in thestructures described which provide the characteristics of this inventionwithout departing from the spirit thereof particularly. as defined in Ithe following claims.

We claim: 1. An apparatus for leveling metal strip material held undertension to correct shape defects therein, said apparatus comprising anelongated supporting guide having a wide base, a narrow flat top portionrelative to said base, tapered sides extending upwardly from said widebase to said narrow flat top portion, curved portionsformed atthejuncture of said tapered sides and said narrow flat top portion, saidcurved portions forming supporting surfaces for tensioned metal stripmaterial bent over said top portion, recesses formed in said flat topportion, a row of capillaries extending upwardly from said wide base incommunication with said recesses in said narrow flat top portion, meansconnected to said elongated supporting guide to supply pressurized fluidto said capillaries extending to said recesses in said flat top portionto impinge against said tensioned metal strip material while holdingsaid metal strip out of contact with said flat top portion to level andcorrect shape defects in said metal strip.

2. A supporting guide (1) for leveling the metal strip as claimed inclaim 1 wherein there are two rows of capillaries (8) for supplyingpressurized liquid provided to said flat portion (36), a slender recess(3) is provided at an exit port (4) of said each capillary (8) and along low projection (38) is provided between two rows of said recesses(3) on said flat portion (36).

3'. A supporting guide (1) for leveling the metal strip as claimed inclaim 1, wherein a fin (10) made of flexible material is attached oneach of said curved portion 4. A supporting guide (1) for leveling themetal strip as claimed in claim 1, the top of said supporting guide (1)ismade of material having lower elasticity than that of the metal.

5. A supporting guide (1) for leveling the metal strip as claimed inclaim 2, wherein the top of said supporting guide (1) is made ofmaterial having lower elasticity said capillaries in the supportingguide to provide pres-' least one hole in each said cham her whichconnect with said capillaries in said supporting guides to supplypressurized liquid thereto.

8. An apparatus as claimed in claim 6, and further including a movablepistonextending into said bed chamber to vary the effective length ofsaid chamber.

9. The apparatus as defined in claim 1, wherein two chambers areprovided in said bed, each having an independent entrance hole throughwhich pressurized liquid is introduced thereinto, means in said bedforming two rows of holes to connect with plural rows of capillaries insaid supporting guides to supply pressurized liquid thereto. v

10. The combination as defined in claim 9, wherein said plural chambersare further divided longitudinally in said bed, each chamber so dividedhaving an independent entrance hole to introduce pressurized liquidthereinto and each having at least one hole which connects with thecapillaries in the supporting guide to which pressurized fluid isprovided.

11. The combination as claimed in claim 9 wherein a pair of pistons areprovided in said chambers, one piston extending into a said respectivechamber from each hole through which pressurized is introduced, and atfective length of said chamber.

1. An apparatus for leveling metal strip material held uNder tension tocorrect shape defects therein, said apparatus comprising an elongatedsupporting guide having a wide base, a narrow flat top portion relativeto said base, tapered sides extending upwardly from said wide base tosaid narrow flat top portion, curved portions formed at the juncture ofsaid tapered sides and said narrow flat top portion, said curvedportions forming supporting surfaces for tensioned metal strip materialbent over said top portion, recesses formed in said flat top portion, arow of capillaries extending upwardly from said wide base incommunication with said recesses in said narrow flat top portion, meansconnected to said elongated supporting guide to supply pressurized fluidto said capillaries extending to said recesses in said flat top portionto impinge against said tensioned metal strip material while holdingsaid metal strip out of contact with said flat top portion to level andcorrect shape defects in said metal strip.
 2. A supporting guide (1) forleveling the metal strip as claimed in claim 1 wherein there are tworows of capillaries (8) for supplying pressurized liquid provided tosaid flat portion (36), a slender recess (3) is provided at an exit port(4) of said each capillary (8) and a long low projection (38) isprovided between two rows of said recesses (3) on said flat portion(36).
 3. A supporting guide (1) for leveling the metal strip as claimedin claim 1, wherein a fin (10) made of flexible material is attached oneach of said curved portion (37).
 4. A supporting guide (1) for levelingthe metal strip as claimed in claim 1, the top of said supporting guide(1) is made of material having lower elasticity than that of the metal.5. A supporting guide (1) for leveling the metal strip as claimed inclaim 2, wherein the top of said supporting guide (1) is made ofmaterial having lower elasticity than that of metal.
 6. In combinationwith the apparatus as claimed in claim 1, a bed attached to the bottomof said supporting guide, means in said bed forming a chamber, anentrance hole formed in said bed chamber whereby pressurized liquid maybe introduced thereinto and plural holes are formed in said bed chamberto connect with said capillaries in the supporting guide to providepressurized liquid thereto.
 7. An apparatus as claimed in claim 6,wherein plural longitudinally divided chambers are formed in said bed,each bed chamber having formed therein an entrance hole through whichpressurized is introduced, and at least one hole in each said chamberwhich connect with said capillaries in said supporting guides to supplypressurized liquid thereto.
 8. An apparatus as claimed in claim 6, andfurther including a movable piston extending into said bed chamber tovary the effective length of said chamber.
 9. The apparatus as definedin claim 1, wherein two chambers are provided in said bed, each havingan independent entrance hole through which pressurized liquid isintroduced thereinto, means in said bed forming two rows of holes toconnect with plural rows of capillaries in said supporting guides tosupply pressurized liquid thereto.
 10. The combination as defined inclaim 9, wherein said plural chambers are further divided longitudinallyin said bed, each chamber so divided having an independent entrance holeto introduce pressurized liquid thereinto and each having at least onehole which connects with the capillaries in the supporting guide towhich pressurized fluid is provided.
 11. The combination as claimed inclaim 9 wherein a pair of pistons are provided in said chambers, onepiston extending into a said respective chamber from each end of saidbed, said pistons serving to change the effective length of saidchamber.